[PATCH v3 10/21] drm/bridge: Clarify the atomic enable/disable hooks semantics

[Boris Brezillon <boris.brezillon@collabora.com>]

The [pre_]enable/[post_]disable hooks are passed the old atomic state.
Update the doc and rename the arguments to make it clear.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
Changes in v3:
* New patch
---
 drivers/gpu/drm/drm_bridge.c | 24 ++++++++++++------------
 include/drm/drm_bridge.h     | 16 ++++++++++++----
 2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index c53966767782..ca74bfe028c9 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -447,7 +447,7 @@ EXPORT_SYMBOL(drm_bridge_chain_enable);
 /**
  * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
  * @bridge: bridge control structure
- * @state: atomic state being committed
+ * @old_state: old atomic state
  *
  * Calls &drm_bridge_funcs.atomic_disable (falls back on
  * &drm_bridge_funcs.disable) op for all the bridges in the encoder chain,
@@ -457,7 +457,7 @@ EXPORT_SYMBOL(drm_bridge_chain_enable);
  * Note: the bridge passed should be the one closest to the encoder
  */
 void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
-				     struct drm_atomic_state *state)
+				     struct drm_atomic_state *old_state)
 {
 	struct drm_encoder *encoder;
 	struct drm_bridge *iter;
@@ -469,7 +469,7 @@ void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
 	list_for_each_entry_reverse(iter, &encoder->bridge_chain,
 				    chain_node) {
 		if (iter->funcs->atomic_disable)
-			iter->funcs->atomic_disable(iter, state);
+			iter->funcs->atomic_disable(iter, old_state);
 		else if (iter->funcs->disable)
 			iter->funcs->disable(iter);
 
@@ -483,7 +483,7 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_disable);
  * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
  *					  in the encoder chain
  * @bridge: bridge control structure
- * @state: atomic state being committed
+ * @old_state: old atomic state
  *
  * Calls &drm_bridge_funcs.atomic_post_disable (falls back on
  * &drm_bridge_funcs.post_disable) op for all the bridges in the encoder chain,
@@ -493,7 +493,7 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_disable);
  * Note: the bridge passed should be the one closest to the encoder
  */
 void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
-					  struct drm_atomic_state *state)
+					  struct drm_atomic_state *old_state)
 {
 	struct drm_encoder *encoder;
 
@@ -504,7 +504,7 @@ void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
 	list_for_each_entry_from(bridge, &encoder->bridge_chain,
 				 chain_node) {
 		if (bridge->funcs->atomic_post_disable)
-			bridge->funcs->atomic_post_disable(bridge, state);
+			bridge->funcs->atomic_post_disable(bridge, old_state);
 		else if (bridge->funcs->post_disable)
 			bridge->funcs->post_disable(bridge);
 	}
@@ -515,7 +515,7 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable);
  * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
  *					the encoder chain
  * @bridge: bridge control structure
- * @state: atomic state being committed
+ * @old_state: old atomic state
  *
  * Calls &drm_bridge_funcs.atomic_pre_enable (falls back on
  * &drm_bridge_funcs.pre_enable) op for all the bridges in the encoder chain,
@@ -525,7 +525,7 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable);
  * Note: the bridge passed should be the one closest to the encoder
  */
 void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
-					struct drm_atomic_state *state)
+					struct drm_atomic_state *old_state)
 {
 	struct drm_encoder *encoder;
 	struct drm_bridge *iter;
@@ -537,7 +537,7 @@ void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
 	list_for_each_entry_reverse(iter, &bridge->encoder->bridge_chain,
 				    chain_node) {
 		if (iter->funcs->atomic_pre_enable)
-			iter->funcs->atomic_pre_enable(iter, state);
+			iter->funcs->atomic_pre_enable(iter, old_state);
 		else if (iter->funcs->pre_enable)
 			iter->funcs->pre_enable(iter);
 
@@ -550,7 +550,7 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable);
 /**
  * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
  * @bridge: bridge control structure
- * @state: atomic state being committed
+ * @old_state: old atomic state
  *
  * Calls &drm_bridge_funcs.atomic_enable (falls back on
  * &drm_bridge_funcs.enable) op for all the bridges in the encoder chain,
@@ -560,7 +560,7 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable);
  * Note: the bridge passed should be the one closest to the encoder
  */
 void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
-				    struct drm_atomic_state *state)
+				    struct drm_atomic_state *old_state)
 {
 	struct drm_encoder *encoder;
 
@@ -571,7 +571,7 @@ void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
 	list_for_each_entry_from(bridge, &bridge->encoder->bridge_chain,
 				 chain_node) {
 		if (bridge->funcs->atomic_enable)
-			bridge->funcs->atomic_enable(bridge, state);
+			bridge->funcs->atomic_enable(bridge, old_state);
 		else if (bridge->funcs->enable)
 			bridge->funcs->enable(bridge);
 	}
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index a608c47d1de5..e814e6d6e7c2 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -266,6 +266,8 @@ struct drm_bridge_funcs {
 	 * bridge's @atomic_pre_enable or @pre_enable function. If the preceding
 	 * element is a &drm_encoder it's called right before the encoder's
 	 * &drm_encoder_helper_funcs.atomic_enable hook.
+	 * This hook is passed the old atomic state (atomic state after new/old
+	 * states have been swapped).
 	 *
 	 * The display pipe (i.e. clocks and timing signals) feeding this bridge
 	 * will not yet be running when this callback is called. The bridge must
@@ -281,7 +283,7 @@ struct drm_bridge_funcs {
 	 * The @atomic_pre_enable callback is optional.
 	 */
 	void (*atomic_pre_enable)(struct drm_bridge *bridge,
-				  struct drm_atomic_state *state);
+				  struct drm_atomic_state *old_state);
 
 	/**
 	 * @atomic_enable:
@@ -292,6 +294,8 @@ struct drm_bridge_funcs {
 	 * bridge's @atomic_enable or @enable function. If the preceding element
 	 * is a &drm_encoder it's called right after the encoder's
 	 * &drm_encoder_helper_funcs.atomic_enable hook.
+	 * This hook is passed the old atomic state (atomic state after new/old
+	 * states have been swapped).
 	 *
 	 * The bridge can assume that the display pipe (i.e. clocks and timing
 	 * signals) feeding it is running when this callback is called. This
@@ -306,7 +310,7 @@ struct drm_bridge_funcs {
 	 * The @atomic_enable callback is optional.
 	 */
 	void (*atomic_enable)(struct drm_bridge *bridge,
-			      struct drm_atomic_state *state);
+			      struct drm_atomic_state *old_state);
 	/**
 	 * @atomic_disable:
 	 *
@@ -316,6 +320,8 @@ struct drm_bridge_funcs {
 	 * bridge's @atomic_disable or @disable vfunc. If the preceding element
 	 * is a &drm_encoder it's called right before the
 	 * &drm_encoder_helper_funcs.atomic_disable hook.
+	 * This hook is passed the old atomic state (atomic state after new/old
+	 * states have been swapped).
 	 *
 	 * The bridge can assume that the display pipe (i.e. clocks and timing
 	 * signals) feeding it is still running when this callback is called.
@@ -329,7 +335,7 @@ struct drm_bridge_funcs {
 	 * The @atomic_disable callback is optional.
 	 */
 	void (*atomic_disable)(struct drm_bridge *bridge,
-			       struct drm_atomic_state *state);
+			       struct drm_atomic_state *old_state);
 
 	/**
 	 * @atomic_post_disable:
@@ -340,6 +346,8 @@ struct drm_bridge_funcs {
 	 * @atomic_post_disable or @post_disable function. If the preceding
 	 * element is a &drm_encoder it's called right after the encoder's
 	 * &drm_encoder_helper_funcs.atomic_disable hook.
+	 * This hook is passed the old atomic state (atomic state after new/old
+	 * states have been swapped).
 	 *
 	 * The bridge must assume that the display pipe (i.e. clocks and timing
 	 * signals) feeding it is no longer running when this callback is
@@ -355,7 +363,7 @@ struct drm_bridge_funcs {
 	 * The @atomic_post_disable callback is optional.
 	 */
 	void (*atomic_post_disable)(struct drm_bridge *bridge,
-				    struct drm_atomic_state *state);
+				    struct drm_atomic_state *old_state);
 
 	/**
 	 * @atomic_duplicate_state:
-- 
2.21.0